Test Aa: No Communication With Remote Emergency Satellite Cellular Unit

1. Turn ignition switch to LOCK position. Disconnect Remote Emergency Satellite Cellular Unit (RESCU) 12-pin harness connector C401a. RESCU module is located, at left side of luggage compartment behind trim panel. Turn ignition switch to RUN position. Measure voltage between ground and RESCU harness connector C401a terminals No. 1 (Red/Black wire) and No. 7 (Pink/Orange wire). See Fig 1 . If battery voltage exists at both terminals, go to next step. If battery voltage does not exist at either terminal, repair power distribution circuit(s) as necessary. See POWER DISTRIBUTION article in WIRING DIAGRAMS.
2. Turn ignition switch to LOCK position. Measure resistance between ground and RESCU harness connector C401a terminal No. 6 (Black/Red wire). If resistance is 5 ohms or less, repair module communications concern. See MODULE COMMUNICATIONS NETWORK - LS. If resistance is more than 5 ohms, repair open in Black/Red wire between RESCU and ground. Ground point is located at right rear of luggage compartment.

Fig 1: Identifying Remote Emergency Satellite Cellular Unit Module Harness Connector Terminals

Courtesy of FORD MOTOR CO.